Devices and methods for reshaping blood vessels

ABSTRACT

Veins and other blood vessels may be reshaped by introducing an implant through the vessel walls with anchors positioned on opposite sides of the wall. The anchors typically include an elongate body having coils or other anchors formed therein. The implants may be delivered percutaneously using a cannula which can hold the anchor externally or internally. The methods and devices are useful in treating a dorsal vein to reduce blood flow in patients suffering from erectile dysfunction.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.15/905,415 (Attorney Docket No. 48624-703.301), filed Feb. 26, 2018,which is a continuation of U.S. patent application Ser. No. 14/732,629(Attorney Docket No. 48624-703.201), filed Jun. 5, 2015, now U.S. Pat.No. 9,918,719, which claims the benefit of Provisional Application No.62/009,267, (Attorney Docket No. 48624-703.101), filed on Jun. 8, 2014,the full disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to system and method for treatingbiological vessels and more particularly reshaping veins and to modifytheir biomechanics in order to allow a reduction in blood flow inresponse to an increase in surrounding blood pressure to modulate flowmodulation.

Venous leaks include various phenomenon where changes in or around thevenous system cause a noticeable clinical impact. For example, the veinshave internal valves that prevent back flow and allow blood flow back tothe heart in the low pressure venous system. Vascular leaks may occur asa vein diameter increases around which can inhibit valve closure(causing a venous leak). Such venous leaks may cause an accumulation ofblood in the lower extremities that in turn may cause discomfort andpain. It is desirable to be able to reshape the vein with the goal ofrestoring the functionality of the valve.

Venous valving also play an important role in penile erection. Penileerection results from increased local blood pressure in the penis. Twocorpora cavernosa located in the penis fill with blood coming from thedeep arteries of the penis. Expansion of the corpora cavernosacompresses the associated outflow veins, thus inhibiting the bloodoutflow and allowing the increased local blood pressure to cause anerection.

In a large percentage of men over age 40, this functionality isimpaired, commonly referred to as erectile dysfunction (ED). While thecause can be an insufficient inflow of blood (arteriogenic ED) in manycases the cause is the incomplete inhibition of venous outflow(venogenic ED). Incomplete venous occlusion typically results fromchanges in the biomechanical behavior of the veins that increaseresistance to pressure.

Presently, ED has limited treatment options. Available medicationstypically increase blood inflow and may not be effective in mensuffering from venous leak. Other treatment options usually involve amajor surgery and complete occlusion of major vein, but such treatmentssuffer from poor long term outcomes. The failure of complete venousocclusion is believed to be caused by the development of collateralveins in response to complete occlusion of the deep dorsal vein and/orother penile veins.

For these reasons, it would be desirable to provide procedures anddevices with improved short term and/or long term results for treatingED and modulating flow through other veins. It would further bedesirable to provide devices for inhibiting venous flow which may beimplanted in relatively simple procedure, particularly outpatientprocedures and procedures that can be performed in a doctor's officewith local or no anesthesia. At least some of these objectives will bemet by the inventions described hereinafter.

2. Description of the Background Art

Methods and devices for treating ED and for modulating blood flowthrough veins and arteries are described in US Patent Publs.2005/0277907; 2011/0066254; and 2011/007458; and U.S. Pat. No.8,240,313. See also Rao and Donatucci (2001) Urologic Clinics28:309-319.

SUMMARY OF THE INVENTION

The present provides methods and devices for inhibiting blood flowthrough a patient's vasculature, particularly through veins but alsofinding use in arterial flow. The methods rely on placing an implantthrough a wall of the blood vessel so that anchors on opposite ends ofthe implant will draw the walls of the vessel together which willreshape or reconfigure a shape of the blood vessel lumen. Often, thereshaped lumen will become more oval than the native lumen. In otherinstances, the new shape will resemble a figure eight or a bow tie. Instill other embodiments, one side of the lumen can be closed to reducethe area of the vessel lumen without necessarily changing the shapewhich may remain generally circular.

In a first aspect, a method according to the present invention forinhibiting blood flow through a vein comprises penetrating an implantinwardly through a proximal location on a wall of the vein. The implantis further penetrated outwardly through a distal location on the wall ofthe vein. The distal end of the implant is anchored on the exteriorsurface of the wall adjacent to the distal location, and similarly aproximal end of the implant is anchored on the exterior surface of thewall adjacent to the proximal location. The anchored ends of the implantare responsible for reshaping the lumen of the veins between the firstand second locations which in turn results in blood flow inhibition.

In an exemplary embodiment, penetrating may comprise advancing a cannulathrough the proximal and distal locations on the wall, where the implantis carried over a distal region from the cannula. Typically, the implantwill comprise an elongate member, such as a wire or ribbon, coiled overthe distal region of the cannula. In such instances, anchoring thedistal end of the elongate member may comprise releasing the distal endafter said distal end is positioned over the exterior surface of thewall adjacent to the distal end. Anchoring of the proximal end willtypically comprise releasing the proximal end of the elongate memberafter the distal end has been released and after the proximal end hasbeen positioned at a preselected distance from the distal end.Alternatively, anchoring the proximal end of the implant may comprisereleasing the proximal end after the proximal end is positioned over theexterior surface of the wall adjacent to the proximal location. In suchcases, anchoring the distal end of the implant will comprise releasingthe distal end after the proximal end has been released and after thedistal end has been positioned at a preselected distance from theproximal end.

In an alternative embodiment, the penetrating may comprise advancing acannula through the proximal and distal locations on the wall, where theimplant is constrained within an interior, typically a lumen or otherpassageway, of the cannula. In such cases, the implant typicallycomprises an elongate member having a distal end pre-shaped into adistal anchor and a proximal end pre-shaped into a proximal anchor. Theelongate member is in a straightened configuration when constrainedwithin the interior of the cannula, i.e. the pre-shaped anchors are bothin a straightened configuration. Anchoring the distal end of theelongate member thus comprises advancing the distal end from the cannulaso that it assumes an anchor configuration over the exterior surface ofthe wall adjacent to the distal location. Similarly, anchoring theproximal end of the elongate member typically comprises releasing theproximal end from the cannula so that it assumes an anchor configurationover the exterior surface of the wall adjacent to the proximal location.The distal end of the elongate member is advanced by advancing a pusherwithin the passageway cannula against a proximal end of the elongatemember, and the proximal end of the elongate member is released byretracting the cannula over said proximal end while it remains engagedagainst the pusher.

While these methods may be utilized for delivering the implants of thepresent invention into a variety of veins and other blood vessels, themethods may find their greatest use in delivering the implants to adorsal vein to treat a patient suffering from erectile dysfunction.

In a second aspect of the present invention, the present inventionprovides implants for inhibiting blood flow through a vein or otherblood vessel. The implant typically comprises an elastic, elongatemember having a distal end and a proximal end. The distal and proximalends are each pre-shaped to assume a delivery configuration whenconstrained and an anchor configuration when unconstrained. The distaland proximal ends, when in their anchor configurations, are separated bya middle region which controls the distance between opposed walls of avein when the implant is implanted in the vein with each anchor on anexterior surface of a wall of the vein. While the distal and proximalends will usually have similar geometries, they can also have differentgeometries, a number of which are illustrated in detail below.

The implants of the present invention will typically comprise anelongate member comprising a wire (or in some cases a ribbon) having acoiled distal end and a coiled proximal end separated by a straightmiddle region. The elongate member may alternatively comprise a wire orribbon having a deflected distal end and a deflected proximal end, e.g.in the shape of an L or J. In still other embodiments, an elongatemember may have an adjustable anchor at each end, e.g. a flange, a cap,or other structure which may be adjusted on a ratcheted surface of theelongate member. In still other embodiments, each end of the elongatemember may be split, forked, or bifurcated to spread open upon releasefrom constraint. In still further embodiments, each end of the elongatemember may have a collapsible disc or other collapsible anchor structurefixed to a central region. In at least most cases, the anchor regions ofthe implants will be deformable or reconfigurable so that they can beplaced in a low profile configuration for delivery and then expandedinto their anchoring configuration when the anchors are exterior to theblood vessel.

The present invention still further provides implant delivery systemsfor the implants just described. The delivery systems will usuallycomprise the implant in combination with a delivery catheter configuredto penetrate opposite walls of a vein. The delivery systems will beconfigured to carry the implant, in a constrained configuration. acrossthe vein or other blood vessel walls, and to release the implant so thatthe distal anchor is positioned against an external surface of a distalside on the wall and the proximal anchor is positioned against anexternal surface of a proximal side on the wall.

In a first embodiment, the cannula of the implant delivery system of thepresent invention comprises an inner needle and an outer mandrel. Thedistal end of the elongate member of the implant is removably secured tothe needle, and the proximal end of the elongate member of the implantis removably secured to the mandrel. In this way, rotation of the needlerelative to the mandrel in a first direction coils the elongate membermore tightly over the cannula and rotation of the needle in an oppositedirection releases the elongate member from the cannula.

In a second embodiment, the cannula of the implant delivery systemcomprises a hollow body and a pusher disposed in a lumen of the hollowbody. The implant is constrained in a straight configuration whenpresent in the lumen of the cannula body, and the implant is releasedfrom the cannula body by advancing the pusher in the lumen relative tothe catheter body. A distal end of the implant will thus be releasedfirst from the needle on a distal side of the target vein or other bloodvessel. After deploying the distal anchor on the distal side of thevein, the needle may be retracted proximally to deploy the proximalanchor on a proximal side of the vein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a general image of blood vessel.

FIGS. 2A-2F shows transverse cross-sections of a blood vessel. FIG. 2Ashows the blood vessel without an implant and FIGS. 2B-2E show differentimplants and placements.

FIGS. 2G and 2H show longitudinal cross-sections of a blood vessel withone implant (FIG. 2G) and two implants (FIG. 2H).

FIGS. 3A-3E different implant designs in accordance with the principlesof the present invention.

FIGS. 4A and 4B show a first embodiment of an implant delivery system inaccordance with the principles of the present invention.

FIG. 5 shows a second embodiment of an implant delivery system inaccordance with the principles of the present invention

FIGS. 6A-6E show an exemplary method for implanting an implant in adorsal vein to treat erectile dysfunction using the implant deliverysystem of FIGS. 5A and 5B.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides an implant for reshaping veins and otherblood vessels in order to change their biomechanical behavior withoutblocking flow, typically inhibiting venous flow to treat conditions suchas erectile dysfunction (ED). The implant has a low profile, isself-conforming to the vein, can be made out of metal or polymer, andcan be delivered to the body using a delivery system. The implant istypically introduced through a venous or other blood vessel wall using apercutaneous delivery method, typically by penetrating a deliverycannula though the vein to place anchors on the implant on distal andproximal external surfaces of the blood vessel wall. Once released fromits delivery system, the implant collapses or otherwise reconfigures toengage opposed outer surfaces of the vessel wall and to draw thesurfaces together. External remodeling of the vessel wall willnecessarily reconfigure the lumen reducing blood flow through the vesselThe implant is not intended to block blood flow.

In one embodiment, the implant comprises of a combination ofintravascular and extra vascular elements. The implant can be deliveredusing a delivery system by piercing the vessel wall. The deliverysystem, or the implant, or both, pierce the vessel wall at least once inorder to implant the device. The implant is initially constrained by thedelivery system and, upon release from the delivery system, the implantassumes its free shape which will reshape of the vessel without blockingthe blood flow. The implant is anchored at at least one location thatcan be inside or outside the vessel wall, usually being anchored at twolocations on opposite external surface locations adjacent to where thevessel has been pierced by the delivery tool. Upon release, the implantforces the vessel to change its shape from an approximately cylindricalshape to an oval or less cylindrical shape than the original shape ofthe vessel, e.g. an oval shape or “bow tie” shape. In some cases it canbe a cylindrical shape with a reduced diameter.

The shape change increases the ability of the vessel to collapse or tofurther change its shape under external forces or pressures at least inone direction. The implant changes the biomechanics of the vessel in thetreated area by modifying the moment of interia to make the vessel moreprone to bending or compressing. While the shape change could lead tosome immediate decrease in blood flow inside the vessel, blood flow isnot blocked. When external forces or surroundings blood pressureincreases and affects the vessel, further decrease in blood flow or evena temporary stop of blood flow will take place compared to the normal ornon-impacted state. The implant may be placed in the vessel temporarilyor permanently depending on the patient's needs as determined by thephysician.

In a first embodiment the implant is made of an elastic metal such as astainless steel alloy, a cobalt based alloys, or a nickel titaniumalloy. The implant can also be made of polymer, such as nylon,polyurethane, a silk-based polymer, or other known polymers. The implantcan be straightened to a low profile shape and constrained in a needletype delivery system. The needle may be used to pierce a superficialtarget vessel (such as the dorsal vein for the treatment of ED),allowing for release of the implant inside the blood vessel. Oncereleased, the implant assumes its free shape. When anchored in one ortwo locations adjacent to the vessel wall, or externally to the vessel,the implant changes its shape and/or reduces its length from theoriginal constrained shape, causing the vessel to change shapes, e.g.,become more oval which makes the vessel more prone to collapsing orcompressing in the direction of its short axis. Under external forces(manual compression or increase in blood flow in the area) the bloodflow in this vessel will decrease is inserted.

In another embodiment, the implant may be formed from a wire, a ribbon,or other elongate body having a free shape that preferably includes amiddle or central portion that will have a low profile when present inthe blood vessel lumen. Such a central portion is usually linear, mayalternatively have an S- or a C-shape, but can also follow a serpentineor meandering line. The implant has one end region in which the generallinear shape of the center portion changes in order to create an extravascular anchoring point that will be larger or different in shape fromthe piercing hole of the vessel in a manner that will keep its endportion externally to the vessel. The implant has another end portionthat can be anchored externally to the vessel in a generally opposingside of the vessel or down or upstream from the first entry point of theimplant. The free size of the implant intravascular portion is smallerthan the original diameter of the vessel in this area hence decreasingthe vessel diameter along the axis of the implant with an end result ofmaking the vessel oval in shape.

In another embodiment the implant may a central elongate region andseparate end caps or anchors at each end that are positioned externallyon the vessel.

In one specific example, the implant can be used to reshape asuperficial vein of 2 mm diameter. In this case the implant will be usedto decrease the diameter of the implant along the axis generally existbetween the entry hole and the exit hole of the implant from the vesselfrom 2 mm to at least 1.8 mm, 1.5 mm or 1 mm or 0.5 mm or until bothwalls of the vessel will come into contact crating a ridge that limitsthe flow in this area but without blocking the flow in the blood vessel.Generally the implant will be used to “ovalize” the vessel by creatingan at least 10% size difference and sometimes an at least 15% differencebetween a long diameter and a short diameter of the vessel cross sectionin the area where the implant.

In another example for a 3 mm vein, the implant length can be 2.5 mmconsisting of a generally linear center portion with end regions toanchor the implant in one or two opposing sides of the vessel. Thisimplant can be straightened to a linear wire constrained and stored,pre-loaded, in a small gauge needle. When straightened the wire lengthof the implant can be as long as 5 mm or even 10 mm depending on theanchor shape and design. The anchors can have a spiral design, typicallyhaving at least one coil, often have more than one coil, to keep the endof the implant anchored external to the vein. The distal end of theimplant can be extravascularly released, embedding an anchor furtheraway from the delivery system. As the delivery system retracts theimplant proximal end will be release out of the vein forming a springlike shape compressing the vein into an oval shape. In this case onlythe central implant portion is released inside the vessel with minimalfootprint exposed to blood flow.

The implant can be made from a metal or polymer wire or other elongatemember. Exemplary wire thicknesses are as small as 10 micron or as largeas 1 mm. Typical ranges are 10 microns to 1 mm, 20 microns to 0.5 mm,and 30 microns to 0.1 mm. For treatment of the dorsal vein, the implantwill typically be at the smaller end of the size ranges. The centralportion of the implant has a length that is smaller than the diameter ofthe vessel to be treated, and the full wire length prior to anchordeployment will usually be longer or even a lot longer than the diameterof the vessel. It is desirable that the footprint of the implant in thearea exposed to blood flow will be minimal or covered with tissue tominimize thrombus formation in the vessel. Anti-thrombotic surfacefinishes or coatings may also be used.

In one embodiment, the implant is formed from a shape memory material,such as a nickel titanium alloy or a shape memory polymer, thatreassumes its free shape in response to a change in temperature or byinducing electrical field or energy field. For small, superficial orsemi-superficial vessels, the implant can be delivered through a smallgauge needle or a small diameter extra vascular delivery system.External guiding such as ultrasonic transducers or imaging or otherknown methods can be used to guide the delivery system to the targetvessel. In other embodiments, the implant will be formed from a materialthat relies on the super elastic propertied to expand in response to arelease from constraint.

Referring to FIG. 1, a typical vein V comprises a tubular vessel havingan outer tunica externa TE, a tunica media TM, and a tunica interna TI.The inner wall of the tunica interna intern is covered with endotheliumE. Veins are also characterized by venous valves VV which allow blood toflow in the direction of arrow VF back toward the heart while preventingblood flow away from the heart. In older individuals, the function ofthe venous valves can sometimes be compromised, and the methods anddevices of the present invention may be particularly useful forimproving valvular performance in such comprised veins. For example, inpatients suffering from erectile dysfunction, the devices and methods ofthe present invention may be used to improve such venous function,particularly in a dorsal vein as described in detail below.

Referring now to FIGS. 2A though 2F, placement of a number of exemplaryimplants can in a vein V will be described. A native vein V, prior toimplantation of an implant according to the present invention, isillustrated in FIG. 2A. Vein V has a generally circular lumen L. Asshown in FIG. 2B, the vein may be deformed to a generally ovoid orrectangular configuration by placement of a first implant 10 a having adistal anchor 12 a and a proximal anchor 14 a on the exterior surfacesof the vein. A central region of the implant between the anchors 12 aand 14 a has a length selected which is less than that of diameter ofthe unconstrained vein, as shown in FIG. 2A. Thus, placement of theanchor will draw the opposed locations on the wall together creating thedesired remodeling or reshaping of the vessel and the lumen.

An alternative implant 10 b having two central regions is illustrated inFIG. 2C. The deformation of the vessel wall is shown to be generally thesame as that in FIG. 2B, but it will be appreciated that by usingdifferent divergence angles and different leg lengths on the implant,the geometry of the deformed vessel can be controlled.

Referring now to FIG. 2D, use of an implant 10C having a much shortercentral portion willcause the opposed wall locationss of the vein V tomore fully collapse, resulting in a figure eight or bow tie crosssection for the vessel.

Referring now to FIG. 2E, in implant 10D similar dimensions to implant10C can be offset toward one side of the vessel, resulting in a partialclosing off of only a portion of the vessel lumen, leaving the otherside of the vessel open but much smaller than the lumen of the nativevessel.

Referring to now FIG. 2F, in implant 10E can be placed through a vinouswall through a region of the vein having a valve VV present.

Referring now to FIGS. 2G and 2H, implants 20, having coiled ends asdescribed more fully below, may be placed at a single location as shownin FIG. 2G or at two or more longitudinally displaced locations, asshown in FIG. 2H.

Referring now to FIG. 3A, a variety of specific designs for differentimplants constructed in accordance with the principals of the presentinvention will be described. The coil implant 20 is shown in some detailin FIG. 3A. The coil implant 20 will usually consist of a single elasticelongate member having a distal coil 22 pre-formed at a distal endthereof and a proximal coil 24 pre-formed in a proximal end thereof. Theelongate member will typically be a wire, more typically being a metalwire formed from an elastic or super elastic metal alloy as describedabove. Alternatively, the elongate member could have other geometricforms, such as being a ribbon, a small diameter helix, (where the coilsat each end would be a second geometric feature with a much largerdiameter than the helical diameter). The elongate member could also beformed from a polymer, typically an elastic polymer and more typically asuper elastic polymer, as is known in the art. The dimensions of thecoil implant 20, including the diameters of the proximal and distalcoils 22 and 24, as well as the distance between the proximal and coils,will be selected based upon the target blood vessel. Specific dimensionsuseful for the dorsal vein are provided hereinafter. The coils 22 and 24are joined by a middle or central region 26 which is generallyintegrated with the coil portions (i.e. the entire coil implant isformed from a single continuous body of material), where the middleportion 26 will define the length between the coil portions. Althoughshown as a straight segment, the middle portion 26 may be curved,serpentine, zig-zag, or have other secondary geometry, but generally astraight profile with minimal “footprint” to disturb blood flow will bepreferred.

A Z-implant 30 is illustrated in FIG. 3B. The Z-implant will alsotypically be formed from a single elongate member, typically a wire or aribbon, having a distal leg 32 and a proximal leg 34 pre-formed therein.Each of the legs will be inclined or deflected relative to an axis of acentral portion 36. When straightened, the legs 32 and 34 will followthe paths shown in broken-line in FIG. 3B. The distal and proximal legs32 and 34 will be in their deflected configuration, as shown in FIG. 3B,after implantation so that the legs act as anchors and deforming thevessel geometry, as described elsewhere herein in detail.

An implant 40 having bifurcated ends is shown in FIG. 3C. The implant 40includes a distal bifurcation 42 which forms a distal anchor and aproximal bifurcation 44 which forms a proximal anchor. The bifurcatedends are joined by a central or middle portion 46 which will usually bestraight but may have other configurations as described above withregards to other embodiments. The bifurcations may be constrained toassume closed configurations as shown in broken-line when the implant isin a delivery configuration and will deploy outwardly, as shown in fullline, when released from constraint to assume an implantedconfiguration.

As described thus far, the implants have generally been formed from asingle elongate member which is then modified to have anchors at eachend. As shown in FIG. 3D, in implant 50 has a distal disc 52 and aproximal disc 54, where the discs will usually be formed from adifferent material and joined to a separate elongate member 56 whichprovides a central or middle region of the implant. For example, thecentral or middle region can be formed from an elastic, metal, orpolymer wire as generally described above, while the discs 52 and 54 maybe formed from a collapsible polymer, metal, or other material. Thediscs 52 and 54 will be collapsible, as shown in broken-line, fordelivery and will self-deploy to the anchoring configuration, shown infull-line.

An implant 60 having adjustably positionable discs 62 and 64 is shown inFIG. 3E. A distal disc 62 forms the distal anchor and a proximal disc 64forms the proximal anchor. A central or middle region 66 is typicallyformed from an elongate member which may be metal, polymer, or any ofthe forms described above. Unlike the earlier implants, the elongatemember which forms the central portion 66 will have a plurality ofdetents or ratchets 68 spaced-apart along its length. Each of theratchets or detents 68 will be able to hold the disc in place afterdeployment. Thus, after the implant 60 has been introduced through thetarget blood vessel, the degree of closure of the vessel can be adjusteddepending on the position of the disc 62 and/or 64 on the shaft of themiddle portion 66. It will be appreciated that further components may beprovided, such as locks, threads, adhesives, and the like, in order tofirmly fix each of the discs 62 and 64 onto the central portion 66 sothat the distance between the discs, once selected, will be reliablymaintained. Alternatively, at least one of the discs 62 or 64 may beleft to be repositionable so that the degree of vessel closure can beadjusted days, weeks, or even longer post-implantation.

A first exemplary implant delivery device 70 is illustration in FIGS. 4Aand 4B. The implant delivery device 70 includes a handle 72, a shaft 74,and a reduced diameter nose portion 75 at a distal end of the shaft. Asbest seen in FIG. 4B, a cannula assembly 76 extends distally from thenose 75 of the implant delivery device 70, and the cannula assemblyincludes a needle 78 and a mandrel 80, where the needle and mandrel arerotatable relative to each other. The needle has a sharp tip 82 whichallows the cannula assembly 76 to be percutaneously or transcutaneouslyintroduced to and/or across vessels, particularly superficial targetveins, such as the dorsal vein as described in detail below. The cannulaassembly 76 can carry any of the implants described above. Asillustrated, the coil implant 20 is carried with the distal coil 28removably attached near the sharp tip 82 of the needle and the proximalcoil 24 removably attached to the mandrel 80. The removable attachmentshold the coil implant 20 in a “constricted” configuration where theelongate body of the implant forms a simple helix extending from the tipof the needle to the distal end of the mandrel. By rotating the needlerelative to the mandrel in a first direction, this temporary helicalconfiguration can be tightened over the needle so that the coil remainsin place during delivery of the coil, as described in more detail below.By counter-rotating the needle relative to the mandrel, the coil implant20 may be released from the delivery device 70.

Referring now to FIG. 5, an alternative implant delivery device 86 isillustrated. Instead of carrying the coil implant 20 over the exteriorof the device, as with the first embodiment, delivery device 86 carriesthe implant in a straightened configuration within a lumen of thedevice. In particular the implant delivery device 86 comprises a cannulaassembly 88 which includes a needle 90 and a pusher 92. The needle 90has a sharpened distal tip 94 which allows percutaneous ortranscutaneous introduction while coil 20 is held within a lumen of theneedle. Once in place through the target vessel, pusher 92 can be usedto advance the coil 20 to release, at first, the distal coil 22 shown inbroken-line. After properly positioning the distal coil 22 relative tothe target vessel, the needle may be proximally withdrawn to positionthe middle region 26 (FIG. 3A) of the coil 20 within the vessel, andthereafter to release the proximal coil 24 over an opposite location onthe exterior wall of the vessel.

Referring now to FIG. 6A-6E, use of the implant delivery device 70 forimplanting a coil implant 20 in a dorsal vein DV for treatment oferectile dysfunction will be described. The cannula assembly 76 of thedelivery device 70 is first positioned adjacent to the dorsal vein DV ina patient's penis P. The dorsal vein DV lies between dorsal arteries DAthen above the corpora cavernosa CC. Position of the urethra U is shownfor reference.

As shown in FIG. 6B, the cannula assembly 76 is aligned with the dorsalvein DV, and the needle 20 is then penetrated distally so that it passesthrough the dorsal vein DV, as shown in FIG. 6C. Typically, the dorsalvein DV will be at least partially collapsed by the penetrating force ofthe needle 78. Once the distal tip of the needle is passed the far ordistal surface of the dorsal vein DV, the needle 78 will be rotatedrelative to the mandrel 80 in order to release the distal coil 22, asshown in FIG. 6B. The needle may then be drawn proximally so that theneedle overlies the proximal surface of the dorsal vein DV, also shownin FIG. 6D. The needle may then be further rotated relative to themandrel 80 in order to release the proximal coil 24 over the proximalsurface of the vein, as shown in FIG. 6E. The needle may then becompletely withdrawn and the procedure can be completed as appropriatefor treating such a percutaneous penetration.

While preferred embodiments of the present invention have been shown anddescribed herein; it will be obvious to those skilled in the art thatsuch embodiments are provided by way of example only. Numerousvariations, changes, and substitutions will now occur to those skilledin the art without departing from the invention. It should be understoodthat various alternatives to the embodiments of the invention describedherein may be employed in practicing the invention. It is intended thatthe following claims define the scope of the invention and that methodsand structures within the scope of these claims and their equivalents becovered thereby.

What is claimed is:
 1. A method for reshaping a native vein to make thevein prone to bending or compression in response to an external force,said method comprising: implanting an elongate member across a generallycircular lumen of the vein, wherein a central region of the lumen has adiameter when the vein is unconstrained; wherein the implant compressesopposed walls of the vein such that a length across the central regionis reduced to less than the diameter of the unconstrained vein but bloodflow in not blocked; and wherein the compressed shape makes the veinmore prone to external forces which cause a decrease or temporarilystoppage of blood flow through the vein.
 2. A method as in claim 1,wherein the lumen of the vein assumes an ovoid or rectangular shape whencompressed by the implant.
 3. A method as in claim 1, wherein implantingthe elongate member comprises: penetrating a distal end of the implantinwardly through an entry location in a wall of the vein and outwardlythrough an exit location on an opposed wall of the vein, deploying adistal anchor of the implant on an exterior surface of the opposed walladjacent to the distal location; drawing proximally on the implant topartially collapse the lumen of the vein; and deploying a proximalanchor of the implant on an exterior surface of the opposed wall tomaintain the partial collapse of the lumen of the vein.
 4. A method asin claim 3, wherein the implant consists of a single wire having acoiled distal anchor and a coiled proximal anchor formed therein.
 5. Amethod as in claim 4, wherein the implant is constrained in astraightened configuration while being penetrated.
 6. A method as inclaim 4, wherein the implant is constrained in a coiled configurationwhile being penetrated.
 7. A method as in claim 5, wherein penetratingcomprises advancing a cannula through the proximal and distal locationson the wall, wherein the implant is carried over a distal region on thecannula.
 8. A method as in claim 4, wherein the coiled distal anchor ofthe implant is initially constrained and released from constraint aftersaid distal anchor is advanced beyond the exterior surface of the walladjacent to the distal location.
 9. A method as in claim 8, wherein thecoiled proximal anchor of the implant is initially constrained andreleased from constraint after the distal anchor has been released overthe distal position while the elongate member remains anchored at itsdistal end.
 10. A method as in claim 1, wherein the implant is anchoredin a dorsal vein to treat a patient suffering from erectile dysfunction.11. An implant delivery system for reshaping a native vein to make thevein prone to bending or compression in response to an external force,said system comprising: a delivery cannula having an interior passagewayand configured to penetrate opposite walls of the vein; an elasticelongate member consisting of a single wire-like body having a distalend pre-shaped to assume an anchor configuration when releasedconstraint and a proximal end pre-shaped to assume an anchorconfiguration when released from constraint, wherein distal and proximalends when in their anchor configurations are separated by a middleregion which controls a distance between opposed walls of a vein whenthe implant is implanted in the vein with each anchor on an exteriorsurface of a wall of the vein, wherein the distance is selected tocompress opposed walls of the vein to deform the vein wall so that thelumen of the vein assumes an ovoid or rectangular shape but blood flowin not blocked.
 12. An implant as in claim 11, wherein the anchorscomprise a coiled distal end and a coiled proximal end separated by astraight middle region.
 13. An implant as in claim 11, wherein theanchors comprise a deflected distal end and a deflected proximal end.14. An implant delivery system as in claim 11, wherein the cannulacomprises an inner needle and an outer mandrel, wherein the distal endof the elongate member is removably secured to the needle and theproximal end of the implant is removably secured to the mandrel so thatrotation of the needle relative to the mandrel in a first directioncoils the elongate member more tightly over the cannula and rotation ofthe needle in an opposite direction releases the elongate member fromthe cannula.
 15. An implant delivery system as in claim 14, wherein thecannula comprises a hallow body and a pusher disposed in a lumen of thehollow body and wherein the implant is constrained to a straightconfiguration when present in the lumen of the cannula body and theimplant is released from the cannula body by advancing the pusher in thelumen relative to the catheter body.
 16. An implant as in claim 11,wherein the distance between the anchors is selected to be 1.8 mm, 1.5mm, 1 mm or 0.5 mm.
 17. An implant as in claim 16, wherein the wire hasa thickness in a range between, 10 microns to 1 mm, 20 microns to 0.5mm, or 30 microns to 0.1 mm.
 18. A method for reshaping a blood vessel,said method comprising: implanting an elongate member across a generallycircular lumen of the blood vessel such that a distal anchor on theimplant engages an exterior surface of a wall of the blood vessel and aproximal anchor on the implant engages an exterior surface of an opposedwall of the blood vessel, wherein the implant compresses opposed wallsof the but blood flow in not blocked; wherein a single straight segmentof the implant extends across the blood vessel lumen with minimaldisturbance to blood vessel flow.
 19. A method as in claim 18, whereinthe implant consists of a single wire having a coiled distal anchor anda coiled proximal anchor formed at each end thereof.
 20. A method as inclaim 18, wherein implanting the elongate member comprises: penetratinga distal end of the implant inwardly through an entry location in a wallof the blood vessel and outwardly through an exit location on an opposedwall of the blood vessel, deploying a distal anchor of the implant on anexterior surface of the opposed wall adjacent to the distal location;drawing proximally on the implant to partially collapse the lumen of theblood vessel; and deploying a proximal anchor of the implant on anexterior surface of the opposed wall to maintain the partial collapse ofthe lumen of the blood vessel.
 21. A method as in claim 20, wherein theimplant is constrained in a straightened configuration while beingpenetrated.
 22. A method as in claim 20, wherein the implant isconstrained in a coiled configuration while being penetrated.
 23. Amethod as in claim 22, wherein penetrating comprises advancing a cannulathrough the proximal and distal locations on the wall, wherein theimplant is carried over a distal region on the cannula.
 24. A method asin claim 20, wherein the coiled distal anchor of the implant isinitially constrained and released from constraint after said distalanchor is advanced beyond the exterior surface of the wall adjacent tothe distal location.
 25. A method as in claim 20, wherein the coiledproximal anchor of the implant is initially constrained and releasedfrom constraint after the distal anchor has been released over thedistal position while the elongate member remains anchored at its distalend.
 26. A method as in claim 18, wherein the implant is anchored in adorsal vein to treat a patient suffering from erectile dysfunction.